Hydraulically controlled, gear operated wrench



March 26, 1957 R. C. BLACKINTON HYDRAULIBJALLY CONTROLLED,- GEAROPERATED WRENCH Filed Sept. 19, 1955 3 Sheets-Sheet l m INVENTOR. mRoamr C BLACK/N rou jM/TH, Omani/ 0m 147" 7" ORNE V5 March 26, 1957 c.BLACKINTON HYDRAULICALLY CONTROLLED, GEAR OPERATED WRENCH 3 Sheets-Sheet2 Filed Supt. 19, 1355 United ms Patent-'0 HYDRAULICALLY CONTROLLED,GEAR OPERATED WRENCH Application September 19, 1955, Serial No. 534,953

3 Claims. (Cl. 81-54) This invention relates to an automatic torquewrench.

The wrench can be used to tighten a clamping fixture on work to bemachined, and it can also be 'used to unloosen a clamping fixture fromclamping engagement with work which has been machined.

In one particular installation each clamping fixture (not part of thepresent invention) is mounted for movement between a work-loadingstation, difierent work-machining stations and a work-unloading station.One or more clamping wrenches are positioned at the work-loadingstation, and a corresponding number of losening" wrenches are positionedat the work-unloading station. The number of wrenches employed at eachstation depends on the size of the work and the necessary dimensions ofthe fixtures. In order that the work can be easily loaded in andunloaded from each fixture, it is necessary that prior to the loading orunloading operation, the wrench be in a retracted position away from thepath which the fixture takes as it approaches the loading and unloadingstations. When the fixture is positioned at the station, a clutchelement on the wrench is caused to advance rectilinearly toward thefixture and engage with a turnable fixture-moving element. Thereafter,the wrench clutch element is automatically turned so as to rotate thefixture-moving element and thereby loosen or tighten the work (dependingon whether the particular wrench is employed at the loading or unloadingstation). Finally the wrench clutch element is retracted rectilinearlyaway from the fixture to await the arrival of the succeeding fixture. I

In most installations the work is loaded and'unloaded at the samestation. In such installations the wrench is employed both as atightening mechanism and loosening mechanism.

One object of the present invention is to provide a torque wrenchwherein a wrench clutch element may be (1) rectilinearly moved towardand into non-slip engagement with a work-clamping fixture, (2) turned totighten and/or loosen the fixture on the work, and (3) retractedrectilinearly away from the fixture.

Another object is to provide a torque wrench having the above mentionedobject and being of compact con struction whereby it may be used in avariety of different installations with little if any structuraladditions or changes.

Another object is to provide a torque wrench for loosening or tighteninga work-holding fixture wherein the wrench can be utilized whether thefixture-moving mechanism is turned in a clockwise or counterclockwisedirection in order to effect the work-tightening or loosening action.This object is achieved by employing a fluid motor mechanism as a powersource for the wrench. Fluid flow in one direction through said motorcauses the Wrench to turn in one direction, and fluid flow through saidmotor in the opposite direction causes reverse turning of the wrench.

Another object is to provide a relatively low cost wrench having goodperformance characteristics.

Another object is to provide a torque wrench including a wrench housingand fluid motor; wherein the'wrench housing is of such construction asto permit securement of the fluid motor thereon in either of twopositions, whereby the motor and fluid conduit means can be positionedout of the way of the wrench operator even though he stands at differentsides of the wrench in various different installations.

Other objects of this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of the specification wherein like reference charactersdesignate corresponding parts in the several views.

In the drawings:

Fig. 1 is an-exterior view of one'embodiment of the invention,

Fig. 2 is a sectional view taken on line 2-2 in Fig. 1,

Fig. 3 is a sectional view taken on line 3-3 in Fig. l, and

Fig. 4 is a sectional view taken on line 4-4 in Fig. 2.

Before explaining the present invention in detail, .it is to beunderstood that the invention is not limited in its application to thedetails of construction and arrangement of parts illustrated in theaccompanying drawings, since the invention is capable of otherembodiments and of being practiced or carried out in various ways. Also,it is to be understood that the phraseology or terminology employedherein is for the purpose of description and not of limitation.

In the drawings there is shown a torque wrench 1 including a housing 2.Housing 2 is provided with an opening 3 (see Fig. 2), and aligned withsaid opening are two bearing assemblies 4 and 5. Bearing assembly 5 hasits outer race 6 fixedly secured in housing 2 and its inner race 7fixedly secured on a sleeve 8. Bearing assembly 4 has its outer race 6slip fitted into opening 3 and its inner race 7 snugly fitted on sleeve8. Extending through sleeve 8 is a shaft 9, and between said shaft andsleeve is a slide-guide means 10 for restricting said shaft to axialmovement relative to the sleeve. Said slide-guide means takes the formof a number of splines 12 integrally formed with shaft 9 and acorresponding number of mating spline keyways 11 formed in sleeve 8.

There is secured over opening 3 a tubular spacer 13,-.

and afiixed to this spacer is a fluid cylinder 14 provided with ports 15and 16. A piston 17 is slidably positioned in cylinder 14, and a pistonrod 18 extends from the piston into fixed securement with one end ofshaft 9. The securement is effected by a dowel 19. It will beappreciated that reciprocal slidable movement of piston 17 (by thepressure action of fluid in cylinder 14) is accompanied by reciprocalslidable movement of shaft 9 in sleeve .8 along the directions of arrows20.

In order to effect the necessary wrenching or turning action shaft 9 isadapted to be rotated by a rotary fluid motor 21. This motor isreleasably mounted on housing 2 by means of bolts 22 and is adapted todrive a multipiece shaft 23. Shaft 23 includes two shaft sections 24 and25, and fixedly secured on shaft section 25 is a worm 26. This wormmeshes with a worm gear. 27'fixedly secured on sleeve 8. It will beappreciated that rotary movement of shaft 23 (by movement of motor 21)will be accompanied by rotation of sleeve 8. Since shaft 9 is slidablykeyed to sleeve 8 at 10 shaft 9 will also be rotated. Shaft 9 is capableof two motions, (l) rectilinearly by hydraulic cylinder 14 and (2)rotatably by fluid motor 21.

There is slidably splined on shaft 9 at 32 a clutch element 28 havingtwo diametrically spaced fingers 29 and 30. These fingers are designedto have their radial faces 31 pressuringly engage corresponding faces ona turnable fixture-moving element (not shown) so as to turn said elementand thereby tighten or loosen the fixture relative to a work piece notshown).

Operation of the illustrated mechanism is such that initially shaft 9 isin a retracted position with piston 17 adjacent port 16. In thisposition clutch element 28 is out of the path of the traveling fixture.When the fixture reaches a position such that its turnable fixturemovingelement is in rectilinear registry with clutch element 28 fluid from asource (not shown) is caused to be introduced into cylinder 14 throughport 16. Shaft 9 is thereby moved rectilinearly to its illustratedposition; During or after this rectilinear movement fluid is passedthrough motor 21 so as to rotate shaft 23 and impart a rotation to shaft9. This rotary movement of shaft 9 causes faces 31 of fingers 29 and 34to pressuringly engage the turnable fixture-moving element and therebytighten or loosen the fixture relative to a work piece.

The wrench may be used to tighten and/or loosen the fixture, accordingas the work is to be loaded and/ or on loaded at the station serviced bythe wrench. if the wrench is employed as both a tightening and looseningmechanism fluid will be alternately introduced into inotor 21 throughdifferent ones of conduits i) and 51, according to the differentdirections in which it is desired to rotate shaft 9.

When clutch element 28 strikes the turnable fixturemoving element duringthe latter portion of the shaft 9 rectilinear movement toward thefixture certain shock forces may be set up in the wrench. These forceswould tend to displace the fixture away from the wrench and/ or causewear on the wrench parts. In order to provide a cushion against theseforces there is provided between element 28 and shaft 9 a compressioncoil spring 35.

After the fixture has been tightened and/or loosened on the work piecefluid is introduced into cylinder 14- through port so as to retractclutch element 28 out of the path of the fixture. During this retractingmovement shaft 9 need not rotate and motor 21 can therefore be in adeenergized condition.

Control of the fluid motor and fluid cylinder is preferably effected bytimer and solenoid valve means, but since these means form no part ofthe present invention they have not been illustrated. A limit switch. 32may be employed in conjunction with the timer means. This switch can beactuated by a spring-urged trigger 33 and a trip ring 34 fixedly securedon rod 113.

With the arrangement of motor 21 and housing 2 shown in Fig. 1 motor 21and/or the conduit means therefore may in some installations projectinto the way of the wrench operator. motor be repositioned in a locationremote from the area occupied by the wrench operator. In this connectionit will be noted that housing 2 is provided with two similar bores 41,52 and two similar bores 53, 54. These sets of similar bores aresymmetrical about axis 43 so as to permit interchange of cover plate andmotor 21. Plate 40 is provided with an extension 44 which fixedly mountsthe outer race 45 of a bearing assembly as. The inner race 47 of saidassembly is fixedly and supportingly secured to shaft section 25.

To cooperate with bearing assembly es in the rotatable support of shaft23 there is provided another bearing assembly 55. Bearing assemblyincludes an inner race 56 fixedly secured on shaft section 2-5 and anouter race 57 fixedly secured in bore 53. Spacer sleeves 58 and 59 areprovided on shaft section 25 in order to In such event it is desirablethat the prevent axial movement of worm 26. A sleeve 60 posi tions race57 in bore 53.

It will be noted that power mechanisms 14 and 21 are both mounted solelyon housing 2 so as to provide a compact construction which may beinstalled as a unit in small and difficultly accessible areas. Therelative positions of motor 21 and cylinder 14 are such that a minimumnumber of drive-transmitting elements are required, whereby to reducethe cost of the wrench.

I claim:

1. A torque wrench comprising a housing; a sleeve rotatably mountedwithin said housing; a first shaft mounted in said sleeve and restrictedto reciprocal axial motion relative thereto; means for effecting saidaxial motion; said housing having a bore therethrough at right angles tothe shaft axis; a rotary motor releasably mounted on the housing andhaving a second shaft extended into said bore; a cover plate releasablymounted on the housing and having an extension received in said bore;bearing means in said extension and supporting the second shaft forrotatable movement; and means between said shafts for translating rotarymovement of said second shaft into rotary movement of the first shaft;said bore and cover plate construction permitting the positions of themotor and cover plate to be reversed.

2. A torque wrench comprising a housing having two openings at rightangles to each other; a fluid cylinder secured on said housing andhaving a piston rod extending therefrom through one of the openings; twobearing assemblies in registry with said one opening; a sleeve fixedlysecured to the inner races of said assemblies, the outer races thereofbeing secured in said housing; shaft in said sleeve and housing andhaving an end portion connected to said piston rod; a clutch on theother end portion of the shaft; slide-guide means between said sleeveand shaft for restricting said shaft to axial movement relative to saidsleeve; a rotary motor secured on said housing and having a second shaftextending through the other opening; and gear means between second shaftand sleeve for translating rotary movement of said second shaft intorotary movement of the first shaft.

3. A torque wrench comprising a housing having two openings at rightangles to each other; a fluid cylinder secured on said housing andhaving a piston rod extending therefrom through one of the openings; asleeve in registry with said rod and rotatably mounted in said housing;a shaft in said sleeve and having an end portion connected to saidpiston rod; a clutch on i118 other end portion of the shaft; slide-guidemeans between said sleeve and shaft for restricting said shaft to axialmovement relative to said sleeve; a rotary motor secured on said housingand having a second shaft extending through the other opening; and gearmeans between said second shaft and sleeve for translating rotarymovement of said second shaft into rotary movement of the first shaft.

References Cited in the file of this patent UNITED STATES PATENTS HolmesMay 10, 1955

